Type 1 diabetes (T1D) is the most common endocrine–metabolic disorder of childhood. Risk factors for type I diabetes include genetic and non–genetic factors). Aim of the work: To study possible non genetic risk factors that might have caused T1D in a group of infants and toddlers (6 months to 2 years of age) presenting to the Diabetes, Endocrine, Metabolic, Pediatric Unit (DEMPU) of Cairo University Children's Hospital. Methods: We used a pre-coded questionnaire filled out by the parent or care-giver to derive the following information: personal history, details of present illness, past history of illnesses or viral infections, vaccination history (compulsory and optional), family history and nutritional history. We compared the results of these children with an equal number of healthy, non-diabetic controls. Results: In total, we reviewed the histories of 200 diabetic children how had developed DM type 1 during infancy and an identical number of controls. All the children with T1D presented with polyurea, polydypsia and weight loss while 74% presented with DKA. A male predominance in T1D cases (67%) was noted in this young age group. Environmental risk factors that appeared to be significant in our study were: room number <3, unclean environments, receiving Hib &Rota virus vaccination (64% compared to 22.5% in controls, 0.003p=), additional doses of polio vaccination above compulsory number (p=0.001), repeated viral infections, history of dehydration, a positive family history of type II diabetes (26.5% compared to 6.0% in controls, p= 0.001), and a family history of gestational diabetes (1% compared to 6 %in controls). Nutritional history revealed that 96% of cases were breast fed (but none exclusively), about 46% were introduced to cow milk and Carbohydrates at 4-6 months (history of cow milk introduction before 1st year of life (99.0% in cases compared to 84.0 % in controls. p= 0.001), introduction of (wheat) before 1st year of life (99.5% in diabetics compared with 93.0% in controls). Sun exposure was significantly less in cases than in controls (<10 min. /day was 60.0% in diabetics compared with <10 min/day 49.0% in controls, p= 0.027) and only 63% of cases received Vitamin D supplementation. There seemed to be a link with the number of vaccinations given, where cases with T1D had had a greater number of extra polio doses above compulsory vaccinations (77.5% in patients compared with 65.0% in controls). Also, exposure to additional vaccines (such as HiB and Rota vaccines) appears to be a possible factor in exposing children to T1D (64.0% in cases compared to 22.5% in controls). Conclusion: Environmental risk factors that seemed to have had a possible role in development of T1D in our cases were: early introduction to cow's milk, poor sun exposure and increased number of vaccines in the first 2 years of life. A history of T2D in the family as well as repeated viral infections also played a possible role